The Genotyping and Molecular Diagnostics Core of the Skin Disease Research Center provides expertise in four essential areas of molecular biology central to the investigation of the genetic basis of human disease. These include 1) Genotyping and haplotype analysis 2) Polymerase chain reaction (PCR) technology 3) Heteroduplex analysis and 4) Mutation verification. Core C will assist center investigators in genotype analysis identifying candidate intervals for genes of interest by linkage analysis to be performed in Core A. Pinpointing genes of interest by haplotype analysis in allelotyping studies will also be accomplished in this Core. Design and optimization of a PCR-based mutation screening strategy for candidate genes of interest will be developed in this Core, as well as mutation detection by heteroduplex analysis. Upon identification of putative areas of the gene of interest containing the mutation, PCR products will be prepared for sequence analysis to be performed In Core D. After sequence analysis has identified mutations, the final service provided by this Core will be in assisting the investigator in verifying the mutation and developing a plan for ascertaining its functional consequence, and the way in which it elicits a clinical phenotype. This Core will interact closely with the other three cores, as its success relies on the acquisition of purified DNA from Core B, accurate linkage analysis in Core A, and fidelitous sequencing and oligonucleotide synthesis in Core D. Further, the expertise offered in this Core will be highly utilized and provide a valuable service to several of the Pilot and Feasibility studies, as well as other NIH-funded investigators within the Department.